Fenugreek (Trigonella foenum-graecum L.) is an annual herbaceous legume suitable for dryland areas where moisture is not sufficient for berseem, for example. Fenugreek plant and seeds have a characteristic strong odour (Ecocrop, 2017). The seeds are used as condiments. Fenugreek is sometimes used as a short-rotation catch crop after sugarcane or cotton.

Morphology

Fenugreek is an erect, smooth, herbaceous plant that can grow up to a height of 40-80 cm (Ecocrop, 2017). It is taprooted. Its stems are erect, up to 50 cm high, sometimes branched. The leaves are alternate, compound, trifoliolate, 7-12 cm long, light green in colour. The leaflets are oval, up to 5 cm long, hairy on their lower face. The flowers are papillonaceous, borne in leaf axils, white, lemon-yellow or purplish blue in colour (Ecocrop, 2017). The fruits occur as straight or sickle-like pods of 2-10 cm, long, thin and pointed, and contain 10-20 seeds. The seeds are 6-8 mm long, oblong or square, green-olive or brownish in colour, with a very strong and spicy odour (Ecocrop, 2017; Alaoui, 2005).

Uses

In ancient times, fenugreek was mainly used as fodder in the Mediterranean Basin. Its Latin name "foenum-graecum" means greek hay. In India, this plant is still grown for fodder. Green parts are highly aromatic and are used as a pot herb and spice. Fenugreek seeds are edible and used as condiments. They yield an oil that is used to flavour butterscotch, cheese, licorice, pickles, rum, syrup and vanilla. The oil is used in perfume and cosmetic industries. The seeds are used as flavouring agents for maple syrup, cheese and curries. They contain diospenin, a drug used in the synthesis of hormones. Seed husks are a source of mucilage, oil, sapogenin and protein. Plant residues or whole plants may be used as green manure and fuel (Ecocrop, 2017; FAO, 2017).

Distribution

Trigonella foenum-graecum originated from South-Eastern Europe and Western Asia (Ecocrop, 2017; Alaoui, 2005). In North Africa, it has been grown for fodder in Saharan oases from very early times (Alaoui, 2005). The Greek named the plant “telis”, which means "green" and the Romans learned from the Greeks that this plant was a valuable fodder (Petropoulos, 2002). Fenugreek is now widespread in India and neighbouring countries, in Northern Africa, Near East, Western Asia, Ethiopia, Chile, Argentina, China and the USA. In the semi-arid regions of North America it is considered a high yielding niche crop (Acharya et al., 2008). In Europe, it is grown in Austria, Belgium, France, Hungary and Spain (Alaoui, 2005).

Fenugreek is naturally found in field verges, uncultivated ground, dry grasslands and hillsides in semi-highland and highland regions (Alaoui, 2005). Fenugreek is grown as a cool season crop in India and the Mediterranean region, both irrigated and as a rainfed crop. It grows on a wide range of preferably well drained soils with a pH ranging from 5.3 to 8.2. Wet soils are not suitable. In cooler areas, growth is slow and weak during cold periods and it is better grown as a summer crop. The seeds require warm dry weather for ripening and harvest (FAO, 2017; Alaoui, 2005). Fenugreek optimally grows in places where annual temperatures are in the range of 8-27°C and where annual rainfall is between 400-1500 mm. It is a full-sunlight species (Alaoui, 2005).

Forage management

Fenugreek is grown and harvested principally for the seeds and only secondarily for forage.

Forage yield

Once a high-valued forage, fenugreek is now a minor forage species (Petropoulos, 2002). There are numerous varieties, adapted to different cultivation conditions, that yield variable amounts of green fodder. Fresh matter yield was about 13-17.5 t/ha in California, and only 9-10 t/ha in India. In this latter country DM yields ranged from 1.5 to 2.75 t/ha in 1975 (Paroda et al., 1975). DM yield was about 5.8 t/ha under rain-fed conditions of Southern Alberta, in Canada. Irrigation did not improve DM yield a lot, with 6 tons DM/ha in Southern Alberta and, exceptionally, 10 tons DM/ha (Mir et al., 1997). After seed harvest, the amount of fenugreek straw was estimated at 1.85 t/ha (Petropoulos, 2002).

Forage management

Sowing

Fenugreek intended for forage can be either sown in spring or autumn, according to climate. As a forage it should be broadcast or drilled at 20-30 kg/ha in pure stands or often mixed with oats. Mixtures with small cereals are best for haymaking (FAO, 2017; Alaoui, 2005).

Time of harvest

Time of harvest should be a trade-off between forage quality and forage yield. If harvested too late, fenugreek sheds its leaves and forage palatability is reduced, while if harvested too early, dry matter content is low and the plant is difficult to cure. The best period of harvest for green fodder is thus when the plant is still tender with only basal pods at the first stage of their development. For hay, the most important goal is to save the most leaves on the stems. This corresponds to pods being in the second stage of their development and containing well formed seeds, which increase the crude protein content of the plant (Petropoulos, 2002).

Methods of harvest

Fenugreek can be hand-cut or mechanically harvested by farm cutting equipment or by conventional mowers, conditioners and rakes. The use of rectangular balers and forage harvesters have also been recommended. If fenugreek is cut under dry conditions, the plant can be left in thin layers to cure on the soil. If harvesting conditions are wet, it is recommended to oven-dry the plant or to make it into silage. Another way to use fenugreek forage is to cut it after seed harvest, forage being thus similar to straw, with a relatively low palatability (Petropoulos, 2002).

Seed management

Seed yield

Seed crop management

When fenugreek is grown for seed it is usually grown in rows about 50 cm apart and thinned to 5-10 cm. The ripe crop is hand-cut, and is often dried on the field before threshing. Seed rates vary widely from 10 to 40 kg/ha, the lower rates being for rainfed crops (FAO, 2017).

Environmental impact

Soil improver and water saver

Trigonella foenum-graecum is an N-fixing plant, thus reducing the need of nitrogen fertilizers for subsequent crops (Acharya et al., 2008). It has low water requirements and its cultivation might reduce the cost of irrigation, save water, reduce the eutrophication of surface waters, and limit the contamination of ground water sources (Basu et al., 2004). Dryland adaptation of fenugreek is of major significance in western Canada and drier parts of the USA as fresh water resources are shrinking in these areas (Acharya et al., 2008).

Methane emissions

Raw and roasted fenugreek seeds added to a mixture of straw and concentrate in the ratio 60:40 resulted in both cases in higher in vitro gas production and in lower methane emissions. It was concluded that 2% raw or roasted seeds of fenugreek had potential to reduce methane emissions from ruminants and to improve DM digestibility (Rejil et al., 2007).

Nutritional aspects

Nutritional attributes

Forage

Fenugreek forage is rich in protein: 15-17% DM and up to 25% DM in the young plant.

Seeds

Tainted milk

Fenugreek was reported to impart a disagreeable taste to milk.

Active secondary metabolites

Fenugreek contains a wide range of active substances such as steroids (diosgenin), N-compounds, polyphenolic substances, volatile constituents, amino acids, etc. No health problems have been reported in animals but some deleterious effects have been shown on reproduction performance (Petropoulos, 2002).

Ruminants

Trigonella foenum-graecum provides a palatable green fodder that was recommended for cattle in ancient history. Marcus Porcius Cato, a Roman authority on animal husbandry in the second century BC, ordered "foenum-graecum" to be used as fodder for oxen (Petropoulos, 2002). Fenugreek forage is highly palatable to livestock (FAO, 2017). Fenugreek seeds are sometimes used as feed additives.

Forage

Nutritive value

Fenugreek can provide high quality forage, comparable to alfalfa forage, at almost all stages of growth. Fenugreek forage grown in greenhouses and cut at 15 and 19 week-old was reported to have higher in vitro DM digestibility than alfalfa at early bloom stage, and similar gas production (Mir et al., 1997). Protein content was higher in the early stages of growth (9 week-old) of fenugreek. Total gas production of mature fenugreek (19 week-old) was similar to that of alfalfa at early-bloom stage, and volatile fatty acids were similar as well (Mir et al., 1997; Mir et al., 1993; Mir et al., 1998).

Fenugreek is both a high quality forage and a dryland adapted crop. In Canada, fenugreek could help beef producers in reducing animal feed requirements through increased feed efficiency, and in reducing water consumption for crop production.

Animal performance

In Canada, steers fed mature fenugreek and steers fed early bloom alfalfa silage supplemented with barley had similar growth performance (Acharya et al., 2008). Moreover, fenugreek had no bloat effect and its diosgenin natural content was thought to have some growth promoting effect (Mir et al., 1998; Mir et al., 1997). These results were in accordance with earlier results which reported that, in spite of higher (+8%) metabolizable energy of alfalfa, steers fed on fenugreek had no different feed intake, weight gain and FCR (Okine et al., 2001).

In lactating dairy cows, two varieties of fenugreek haylage could be prepared in a similar way to alfalfa haylage and fed at 40% on haylage. One of the two varieties could compare with alfalfa haylage for ruminal degradation and digestion in the rumen, in the intestine and over the whole tract (Doepel et al., 2012). However, feeding cows with fenugreek haylage (of both varieties) resulted in lower DM intake and subsequent milk production, milk protein yield and milk lactose yield. However, short chain fatty acids and hypercholesterolemic fatty acids were reduced (Alemu et al., 2011).

Seeds

Buffaloes

Feeding Milch Murrah buffalo cows on fenugreek seeds and a mixture of jaggery (cane sugar) and pearl millet after calving was reported as a common practice in Indian Haryana State during the Rabi season (October to March). It was shown that the ration could meet animal protein and energy requirements (Singh et al., 2001).

Dairy cows

Fenugreek seeds were included in dairy cow rations during 3 weeks at up to 20% of the DM. Dairy cows fed on fenugreek seeds had lower body weight but could not be considered significant. Fenugreek seeds had no effect on milk yield (slightly increased fat-corrected milk yield) and had no impact on milk flavour or taste. It reduced animal blood cholesterol (-4% compared to the control) and milk cholesterol by 15% (Shah et al., 2004).

Sheep

In the last 3 weeks of pregnancy, Awassi ewes were fed on isonitrogenous, isoenergetic rations including either control, either Nigella sativa seeds, or fenugreek seeds, or a mixture of the two seeds. The ration containing fenugreek seeds or the mixture of fenugreek and nigella seeds resulted in higher milk yield, protein milk yield and lambs weights. There was no effect on animal health (Al-Rawi et al., 2014). A former experiment intended to measure the effect of fenugreek seeds on digestibility and milk production had provided consistent results (Saleh, 2004). Barki ewes in the last 4 weeks of pregnancy and Barki rams were offered a berseem (2 kg/d) and rice straw (0.25 kg/d) based diet with 0.9 kg concentrate, to which fenugreek seeds were added at two levels, 20 g/d and 40 g/d. Total DM intake increased only at the lower level of fenugreek seeds, and the higher level decreased DM intake in comparison to control. However, even at the higher level, fenugreek seeds improved nutrient (DM, CP, OM, NFE and EE) digestibilities but CF digestibility in rams. In ewes, milk yield, fat-corrected milk and feed efficiency were improved. Weaning weight and average daily gain of suckling lambs were improved by fenugreek seeds addition (Saleh, 2004).

Goats

Saudi goats in early lactation were offered 60 g/d fenugreek seeds during 7 weeks. Fenugreek seeds increased milk yield and growth hormone level, while it significantly reduced glucose and urea levels in plasma. It was suggested that the milk yield enhancement was due to the growth hormone increase (Alamer et al., 2005).

Baladi goats fed on a mixture of seeds of fenugreek, black cumin, caraway and garden cress at 8 or 16 g/d had increased milk yield (+14.8 and +17.8% respectively) in comparison to control. Milk fat and protein yields were increased but other elements of milk composition remained unchanged. Animal blood analyses showed a trend to having lower cholesterol (Kholif et al., 2004).

Ethnoveterinary medicine

Fenugreek (Trigonella foenum-graecum) seeds have been assessed in rats for the hepatoprotective effect they could have against aluminium chloride contaminated animals. It was shown that the inclusion of fenugreek seed powder at 5% in pelleted diets during two months alleviated the deleterious effect of aluminium chloride on rats liver at blood and histologic levels. It could make a valuable detoxifying diet supplement for contaminated animals (Belaïd-Nouira et al., 2013).

Fenugreeek leaf and seed extract at 130 mg/mL could kill all Gastrothylax crumenifer, an amphistome parasite that causes paramphistomiasis in domestic ruminants worldwide. It could be a cheap way to control this disease in smallholder herds (Swarnakar et al., 2014).

Pigs

Only information about the use of fenugreek seeds as feed additives for pigs could be found (as of 2017).

Poultry

Only information about the use of fenugreek seeds as feed additives for poultry could be found (as of 2017).

Rabbits

Forage

Because green fenugreek (Trigonella foenum-graecum) is highly palatable to rabbits or hares, it was recommended to protect the fenugreek crops with a net in case of severe attacks, especially in experimental plots (Hardman, 1978 cited by Manicas, 2002). Fenugreek forage (green or hay) is a potential source of protein for rabbits (15-16% up to 25% in the DM of the young plant), with a moderate level of fibre. However, no direct experimentation on its use in rabbit feeding seems available in the international literature. As most of legume forages, fenugreek proteins have a low content of sulphur-containing amino acids and phosphorus.

Seeds

Fenugreek seeds were studied in rabbit feeding mainly as a "feed additive", with an incorporation level of 0.5% to 1.5% (Eiben et al., 2004; Omer et al., 2012; Zeweil et al., 2015; Sharma et al., 2017). Fenugreek seeds introduced at such levels in growing rabbit diets are claimed to act as growth promoter, increasing feed intake, growth rate and feed conversion, without any modification of slaughter yield (Zeweil et al., 2015). Unfortunately no information seems available on the consequences of fenugreek seeds inclusion on the taste of rabbit meat. The seeds have generally significant hypoglycemic, hypolipidemic, diuretic and galactagogue effects, as demonstrated by studies in laboratory conditions (Al-Atwi, 2010). The 3 first effects were assessed by many experiments conducted with various animals including rabbits. However, the galactagogue effect observed with lactating goats (Al-Shaikh et al., 1999; Alamer et al., 2005) was not observed with lactating rabbit does (Eiben et al., 2004), or only during the third week of lactation, but without significant effect on litter weight at 28 days (Rashwan, 1998). Nevertheless the inclusion of 1.2% fenugreek seeds in the diet reduced the kits preweaning mortality (Rashwan, 1998).

With a higher incorporation level (5%) in the diet of rabbits raised in hot conditions (Egypt), fenugreek seeds improved heat resistance of adult male rabbits, particularly if the diet was distributed at night. Libido, semen and fertility are all significantly improved in comparison to the control (Daader et al., 2004).

Feeding fenugreek seeds at 30% of the diet for 3 months showed no significant effect on liver function nor on body weight and body gain of both male and female rabbits, but resulted in important reproduction disturbances in males and in females (Kassem et al., 2006). However, whether these deleterious effects are due to fenugreek or to diet imbalance induced by the substitution (such as a deficiency in sulphur-containing amino acid) is unknown.

Sprouted seeds

Gilthead seabream (Sparus aurata)

Fenugreek seeds were used to feed gilthead seabream fingerlings (8 g BW). The highest inclusion level of 10% (DM basis) was found to be optimal for the improvement of the immune status of the fish, and for fish growth performance. No ill effects were detected during the experiment (Awad et al., 2015).

Nile tilapia (Oreochromis niloticus)

Small amounts of fenugreek seeds (1% and 2%), thus rather considered as feed additives, increased the specific growth rate and feed utilization of fry and adult Nile tilapia (Oreochromis niloticus) in comparison to the control diet (Abdelhamid et al., 2012; Zaki et al., 2012).